Electronic writing instrument, computer system, electronic writing method and computer readable medium

ABSTRACT

The electronic writing instrument is provided with: a writing unit that writes down on a medium where a code indicating identity information and location information of the medium is formed; an emitting unit that emits light to the medium; a photoelectric conversion unit that includes photoelectric conversion element receiving a reflected light from the medium by the light emitted by the emitting unit and outputting an electronic signal after converting the reflected light by photoelectric conversion; a receiving unit that receives a user operation; and a condition changing unit that changes at least any one of an emitting condition of the emitting unit to the medium and an output condition of the photoelectric conversion unit when the receiving unit receives an operation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.12/058,272 filed Mar. 28, 2008, which is based on and claims priorityunder 35 USC §119 from Japanese Patent Application No. 2007-129668 filedMay 15, 2007.

BACKGROUND

1. Technical Field

The present invention relates to an electronic writing instrument, acomputer system, an electronic writing method and a computer readablemedium storing a program used for computerizing a writing operation to amedium such as a sheet of paper.

2. Related Art

Using a sheet whose surface includes a printed code image formed fromvarious different patterns and a pen device in which an image pickupdevice is embedded, the pen device is used for writing on the sheet andthe code images corresponding to a written character, a figure and thelike are read into the image pickup device.

SUMMARY

According to an aspect of the invention, there is provided an electronicwriting instrument including: a writing unit that writes down on amedium where a code indicating identity information and locationinformation of the medium is formed; an emitting unit that emits lightto the medium; a photoelectric conversion unit that includesphotoelectric conversion element receiving a reflected light from themedium by the light emitted by the emitting unit and outputting anelectronic signal after converting the reflected light by photoelectricconversion; a receiving unit that receives a user operation; and acondition changing unit that changes at least any one of an emittingcondition of the emitting unit to the medium and an output condition ofthe photoelectric conversion unit when the receiving unit receives anoperation.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiment (s) of the present invention will be described indetail based on the following figures, wherein:

FIG. 1 shows an example of a configuration of a writing informationprocessing system to which the exemplary embodiment is applied;

FIGS. 2A to 2C are diagrams for explaining the code pattern images;

FIG. 3 shows a configuration of the digital pen;

FIG. 4 shows a configuration of the infrared LED unit shown in FIG. 3;

FIG. 5 shows a configuration of the infrared CMOS shown in FIG. 3;

FIG. 6A is a block diagram of a configuration of the controller shown inFIG. 3;

FIG. 6B is a block diagram of a configuration of the image processorshown in FIG. 6A;

FIG. 7 shows a carte form of a carte sheet as an example of the printedmaterial;

FIG. 8A is a flowchart showing the flow of the operation setting of thedigital pen in the writing mode;

FIG. 8B is a flowchart showing the flow of the operation setting of thedigital pen in the reference information acquiring mode;

FIG. 9A shows an example of the first light emitting condition and thesecond light emitting condition which are set in the infrared LED unit;

FIG. 9B shows an example of the first light receiving condition and thesecond light receiving condition which are set to the infrared CMOS; and

FIG. 9C shows an example of the first image processing condition and thesecond image processing condition which are set to the image processor.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the attached drawings.

FIG. 1 shows an example of a configuration of a writing informationprocessing system to which the exemplary embodiment is applied. Thewriting information processing system according to the present exemplaryembodiment is configured to include a terminal apparatus 100 thatinstructs an image forming apparatus 400 to print an electronicdocument, a document server 200 that stores the electronic document, andthe image forming apparatus 400 that prints an image in which a codepattern image is superimposed on an electronic document image.

The writing information processing system according to the presentexemplary embodiment further includes a printed material 500 as anexample of a medium that is outputted by the image forming apparatus400, a digital pen 600 as an example of a pen device that records acharacter or a figure onto the printed material 500 and also reads atrace of the recorded character or the figure, and a terminal apparatus700 as an example of an information processing apparatus that displaysthe trace received from the digital pen 600 superimposed on anelectronic document received from the document server 200.

In addition, in the writing information processing system according tothe present exemplary embodiment, the terminal apparatus 100, thedocument server 200, the image forming apparatus 400 and the terminalapparatus 700 are interconnected via a network 900 with each other. Thedigital pen 600 is connected with the terminal apparatus 700 via awireless network (not shown in the figure).

An operation of the writing information processing system according tothe present exemplary embodiment is outlined below.

First, the terminal apparatus 100 acquires an electronic document thatis to be printed, from the document server 200 (A). Then, the terminalapparatus 100 instructs the image forming apparatus 400 to print theelectronic document (B). At this time, the terminal apparatus 100specifies a print attribute which is a parameter concerning theprinting. This print attribute includes a sheet size, a direction,both-side printing and the like, similarly to the case in the normalprinting. With respect to the code image, that is, a code pattern image,specification of an area on which the code pattern image is printed orthe like may be included.

When receiving an instruction to print the electronic document, theimage forming apparatus 400 outputs the printed material 500 as a paperor the like on which the code pattern image superimposed on anelectronic document image is printed (C). In this case, the code patternimage is an image generated from both an identity code corresponding tothe identity information and a location code corresponding to thelocation information. Alternatively, the code pattern image may be animage generated from them and additional information as otherinformation. The processing of superimposing the code pattern image onthe electronic document image may be carried out in the terminalapparatus 100 or in the image forming apparatus 400.

Here, as the identity information, information that uniquely identifieseach medium is adopted. For example, it may be information acquired bycombining an identity number of the image forming apparatus 400 with aserial number for printing the medium in the image forming apparatus 400or printing date and time, or information centrally managed so that noduplication occurs on a predetermined server. Alternatively, as theidentity information, information that does not uniquely identifies eachmedium but that uniquely identifies an electronic document printed onthe medium may be adopted.

The location information indicates information for specifying acoordinate location (X-coordinate, Y-coordinate) on each medium. Forexample, the coordinates may be represented with a coordinate system inwhich the origin is set as the left top point of the medium, X-axis isset as the right direction of the medium and Y-axis is set as thedownward direction.

Further, additional information may include identity information of auser who instructs to print and information of copy prohibition.

The image forming apparatus 400 forms a code pattern image as aninvisible image using invisible toner having an infrared lightabsorption rate of a certain level or higher. On the other hand, adocument image of the electronic document is preferably formed as avisible image using visible toner with an infrared light absorption rateof a certain level or lower. The difference in infrared light absorptionrate is set between toner used to form the code pattern image and tonerused to form a document image so that the reading precision at thereading of the code pattern image by infrared light emitting by thedigital pen 600 or the like is secured. In the present exemplaryembodiment, description will be given with the reading of a code patternimage by infrared light emitting as a premise. However, the reading ofthe code pattern image by ultraviolet light emitting may be alsoallowed.

Assume a case where a user thereafter uses the digital pen 600 to writecharacters or figures onto the printed material 500 (D). When the useruses the digital pen 600 to write a character and a figure on theprinted material 500, the digital pen 600 is set to a writing mode whichis an example of a first acquiring mode in the present exemplaryembodiment as later mentioned. At this time, the digital pen 600performs a writing operation on the printed material 500 and emits aninfrared light on the printed material 500 at the same time, and aninfrared image is inputted to the digital pen 600 by detecting reflectedlight thereof. Then, the digital pen 600 acquires information from theinfrared image and, via wireless communication, sends the information tothe terminal apparatus 700 (E). The information sent here includes, forexample, the identity information for the printed material 500, and thelocation information of the written character or figure on the printedmaterial 500.

Then, the terminal apparatus 700, based on the identity informationreceived from the digital pen 600, acquires an electronic document whichis a source of the document image printed on the printed material 500from the document server 200 (F). Then, the terminal apparatus 700displays the information acquired from the digital pen 600 superimposedon the electronic document acquired from the document server 200.

Assume a case where a user checks a specific area of the printedmaterial 500 using the digital pen 600 (G). When a digital pen 600 isused to check the specific area of the printed material 500, it is setto the reference information acquiring mode which is an example of asecond acquiring mode in the present exemplary embodiment latermentioned. At this time, the digital pen 600, similarly to the case ofthe writing mode, emits an infrared light on the printed material 500,and an infrared light image is inputted to the digital pen 600 bydetecting the reflected light thereof. The digital pen 600 acquiresinformation from the infrared image, and, via the wirelesscommunication, sends the information to the terminal apparatus 700 (E).The information sent here includes, for example, the identityinformation for the printed material 500 and the location information ata specific area checked out of the printed material 500. In thereference information acquiring mode, a writing operation on the printedmaterial 500 may be performed, or may not be performed.

Then, the terminal apparatus 700, based on the identity information andthe location information received from the digital pen 600, acquires anelectronic document corresponding to the identity information and thelocation information, from the document server 200 (F). Then, theterminal apparatus 700 displays the electronic document acquired fromthe document server 200.

Here, when the identity information received from the digital pen 600 isthe information that uniquely identifies each medium, in order toacquire an electronic document based on the identity information, it isnecessary to manage correspondence relationship between the identityinformation and the electronic document. In the writing informationprocessing system shown in FIG. 1, a portion that manages such thecorrespondence relationship is not clarified, but any portion may manageit as far as it is accessible from the terminal apparatus 700. Forexample, it may be the document server 200 or the image formingapparatus 400. If the identity information received from the digital pen600 uniquely identifies an electronic document printed on the medium,the electronic document is acquired without referencing such thecorrespondence relationship.

In the writing mode, if the terminal apparatus 700 receives traceinformation from the digital pen 600, the trace information is displayedso that the trace information is superimposed on the location of theelectronic document corresponding to the writing location on the printedmaterial 500. Since the location information is included in the codepattern image read by the digital pen 600, the location informationspecifies the corresponding location on the display image of theelectronic document.

On the other hand, in the reference information acquiring mode, in orderfor the terminal apparatus 700 to acquire an electronic document basedon the identity information and the location information received fromthe digital pen 600, the correspondence relationship of the identityinformation and the location information with electronic document mustbe managed. In the writing information processing system shown in FIG.1, a portion that is to manage such the correspondence relationship isnot clarified, but any portion may manage it as far as it is accessiblefrom the terminal apparatus 700. For example, it may be the documentserver 200 or the image forming apparatus 400.

The above mentioned configuration of the writing information processingsystem to which the present exemplary embodiment is applied is only anexample. For example, processing for superimposing the code patternimage on the electronic document image is configured so as to beperformed by a device such as a server computer that relays the printinstruction from the terminal apparatus 100 to the image formingapparatus 400. The document server 200 may be installed in the terminalapparatus 100. Further, the terminal apparatus 100 and the terminalapparatus 700 may be configured in the same terminal apparatus.

In the present exemplary embodiment, the term “electronic document” isused. However, it does not only indicate electronic data of a documentincluding a text. For example, the “electronic document” includes imagedata (not depending on raster data or vector data) such as pictures,photographs, figures and the like, and other electronic data (electronicdocument) used for printing.

Next, code pattern images printed by the image forming apparatus 400 aredescribed below.

FIGS. 2A to 2C are diagrams for explaining the above mentioned codepattern images. FIG. 2A schematically shows a two-dimensional codearrangement formed as an invisible image. FIG. 2B shows an expandeddiagram of the two-dimensional code, which is a unit of thetwo-dimensional code arrangement shown in FIG. 2A. Further, FIG. 2C is adiagram for explaining pattern images of a backslash “\” and a slash“/.”

In the present exemplary embodiment, the code pattern images shown inFIGS. 2A to 2C are formed by using an invisible image forming materialhaving an absorption wavelength in an infrared region. The code patternimages shown in FIGS. 2A to 2C are formed by transparent toner having,for example, the maximum absorption rate of not more than seven (7)percents in the visible light region (400 nm to 700 nm) and anabsorption rate of not less than 30 percents in the near infrared region(800 nm to 1000 nm) as an example of the invisible toner. In addition,in order to increase an ability of the absorption in the near infraredregion that is necessary for mechanically reading of an image, theinvisible toner, as an example of the image forming material, having 100nm to 600 nm as a range of an average dispersion diameter is adopted.Here, with regard to “visible” and “invisible,” they are independent ofrecognition with eyes. “Visible” and “invisible” are differentiatedbased on whether an image formed on the printed medium has a chromogenicproperty due to absorption of a specific wavelength in the visible lightregion. Additionally, “invisible” includes the region that is difficultto be recognized with human eyes and that has a little chromogenicproperty due to absorption of the specific wavelength in the visiblelight region.

As described above, in the present exemplary embodiment, a code patternimage is formed by transparent toner that is an example of the invisibletoner so that tone of the image printed on a medium is not affected andthe identity information and the location information are embedded.

The code pattern image provides a stable operation of mechanical readingand the decoding processing with an infrared light emission for the longterm, and is formed with an invisible image that records informationwith high density. It is also preferable that the invisible image givesless noise to the visible image on the surface of the medium on whichthe image is outputted. Moreover, for example, it is preferable that theinvisible image is discriminated in terms of brightness difference froman area in which no images are formed. For example, an invisible imageis formed on the entire surface of the medium (paper surface) whilebeing adjusted with the size of the printed medium. However, “the entiresurface” does not indicate that four corners of the sheet are allincluded. In an image forming apparatus using an electrophotographicmethod or the like, since the peripheral area of a paper sheet isusually unprintable, even if there is no printed invisible image on theperipheral area, an image is regarded as an image formed on “the entiresurface.”

The two-dimensional code shown in FIG. 2B includes an area that storeslocation codes indicating the coordinate location on the medium and anarea that stores identity codes that uniquely specify a medium and thelike. It also includes an area that stores synchronous codes. As shownin FIG. 2A, plural two-dimensional codes are arranged on a surface ofthe medium in a grid pattern. That is, on the surface of the medium, theplural two-dimensional codes as shown in FIG. 2B are arranged, each ofwhich has the location codes, the identity codes and the synchronouscodes. The area for the plural location codes stores the locationinformation that is different by the arranged location. On the otherhand, the area for the plural identity codes stores the same identityinformation independent of the arranged location.

In FIG. 2B, the location codes are arranged within a rectangle area of 6bits by 6 bits. Each bit value is formed by a bitmap of plural minutelines with different rotation angles so as to represent bit values zero(0) and one (1) in the pattern image (a pattern 0 and a pattern 1) asshown in FIG. 2C. More specifically, using the backslash “\” and theslash “/” which have different inclination angles with each other, bitvalues 0 and 1 are represented. The pattern image has a size of 8 pixelsby 8 pixels with 600 dpi, and a pattern image having a rising diagonalstroke from bottom right to top left (the pattern 0) represents the bitvalue 0, whereas a pattern image having a rising diagonal stroke frombottom left to top right (the pattern 1) represents the bit value 1.Thus, the different inclination angles of the pattern images representone bit information (0 or 1).

In other words, the location code area shown in FIG. 2B stores thelocation information of 36 bits in total. According to the presentexemplary embodiment, 18 bits out of 36 bits are used for encodingX-coordinate and the other 18 bits are used for encoding Y-coordinate.If 18 bits each is fully used for encoding the locations, 2¹⁸(approximately 260 thousand) locations are encoded. In the presentexemplary embodiment, each pattern image is composed of 8 pixels by 8pixels (with 600 dpi), as shown in FIG. 2C. One dot size for 600 dpi isapproximately 0.0423 mm, thus the size of the two-dimensional code(including the synchronous codes) in FIG. 2B is approximately 3 mm (8pixels×9 bits×0.0423 mm) in length and width. If 260 thousand locationsare encoded with 3-mm interval, the length of about 786 m is encoded. Inthis way, 18 bits all may be used for encoding locations, or ifdetection of the pattern image causes an error, redundant bits for errordetection and error correction may be included.

The identity codes are arranged within rectangle areas of 2 bits by 8bits and 6 bits by 2 bits, and stores the identity information of 28bits in total. If 28 bits are used for the identity information, 2²⁸types (about 270 million types) of the identity information arerepresented. The identity code may include redundant bits within 28 bitsfor error detection and error correction, similarly to the locationcode.

In an example as shown in FIG. 2C, two pattern images have angulardifference of 90 degrees each other. If the angular difference is set to45 degrees, four pattern images are formed. If such pattern images areformed, the pattern images represent information of two bits (0 to 3).In other words, by increasing variation of angles for pattern images,bit number to be represented may be increased.

In another example shown in FIG. 2C, encoding a bit value is explainedusing pattern images. However, other way than pattern images may beadopted. For example, a bit value may be encoded by using ON or OFF ofdots or a direction of a dot deviated from a reference position.

Next, the digital pen 600 according to the present exemplary embodimentis described.

FIG. 3 shows a configuration of the digital pen 600. As shown in thefigure, the digital pen 600 has a controller 61 that works as a changingunit and a condition changing unit to control all the pen operations. Tothe controller 61, a pressure sensor 62 that detects a writing operationof the digital pen 600 by detecting a pressure applied to a pen tip 69which functions as an example of a writing unit according to the presentexemplary embodiment is connected. Further, to the controller 61, aninfrared LED (Light Emitting Diode) unit 63 that emits an infrared lighton a medium and an infrared CMOS (Complementary Metal OxideSemiconductor) 64 that reads a code pattern image by detecting aninfrared reflected light from the printed material 500 are connected.Furthermore, to the controller 61, an information memory 65 for storingthe identity information, the location information and the additionalinformation, a communication unit 66 for communicating with externalapparatuses such as the terminal apparatus 700, a battery 67 for drivingthe pen, and a switch 68 that receive switching of an operation mode forthe digital pen 600 are also connected. In the present exemplaryembodiment, an acquiring unit is configured by the controller 61, theinfrared LED unit 63 and the infrared CMOS 64 and so on.

Here, in the present exemplary embodiment, the switch 68 that functionsas a receiving unit is the one that receives a switching operationbetween the writing mode and the reference information acquiring mode bya user. For example, a condition in which the switch 68 is not pressedmay be set to “the writing mode,” whereas another condition in which theswitch 68 is once pressed may be set to “the reference informationacquiring mode.” If the switch 68 is further pressed one more time, thecondition returns to “the writing mode.”

FIG. 4 shows a configuration of the infrared LED unit 63 shown in FIG.3.

The infrared LED unit 63 that functions as an example of an emittingunit according to the present exemplary embodiment includes a substrate63 a and three infrared LEDs (light-emitting diodes) that are mounted onthe substrate 63 a, that is, a first infrared LED 631, a second infraredLED 632 and a third infrared LED 633. The first infrared LED 631, thesecond infrared LED 632 and the third infrared LED 633 are arranged in atriangular shape. Each of the first infrared LED 631, the secondinfrared LED 632 and the third infrared LED 633 emits a light with awavelength (850 nm in the present exemplary embodiment) corresponding tothe absorption wavelength in the infrared region of the code patternimages formed on the printed material 500.

FIG. 5 shows a configuration of the infrared CMOS 64 shown in FIG. 3.

The infrared CMOS 64 that functions as an example of a photoelectricconversion unit according to the present exemplary embodiment includesan infrared CMOS chip 641, a lead frame 642 that is electricallyconnected with the infrared CMOS chip 641, and a package unit 643 thatintegrates the infrared CMOS chip 641 and the lead frame 642 in a resinmold.

The infrared CMOS chip 641 has plural photo transistors arranged invertical and horizontal directions in a matrix pattern. The infraredCMOS chip 641 outputs a received-light data with a so-called XYaddressing method in which the output of the received-light data isselected per cell. As a result, the infrared CMOS chip 641 arbitrarilyselects and outputs, among all received-light data of each cell, forexample, received-light data of cells installed in a first lightreceiving area 644 and, for example, received-light data of cellsinstalled in a second light receiving area 645 that is larger than thefirst light receiving area 644. Since the infrared CMOS chip 641 adoptsthe XY addressing method, the received-light data from all linesconfigured by cells and, for example, the received-light data from ahalf number of lines that is every other lines in all lines arearbitrarily selected and outputted. In this case, if the former outputresolution is, for example, 600 dpi, the latter output resolution of thereceived-light data decreases to a half of the former output resolution,that is, 300 dpi.

As shown in FIG. 3, the infrared CMOS 64 receives an infrared reflectedlight that is emitted from the infrared LED unit 63 and then that isreflected by the printed material 500. In the present exemplaryembodiment, the infrared CMOS 64 is configured so as to receive adiffusely reflected light among an infrared reflected light from theprinted material 500.

FIG. 6A is a block diagram of a configuration of the controller 61 shownin FIG. 3.

The controller 61 includes an administrative controller 611, a lightemitting controller 612, a light receiving controller 613 and an imageprocessor 614.

The administrative controller 611 performs administrative control on thelight emitting controller 612, the light receiving controller 613 andthe image processor 614 based on signals inputted from the pressuresensor 62 and the switch 68. The administrative control includes varioussetting changes according to the mode switching between the writing modeand the reference information acquiring mode. The light emittingcontroller 612 that functions as an example of emitting setting unitaccording to the present exemplary embodiment controls a light emittingoperation of a first infrared LED 631, the second infrared LED 632 andthe third infrared LED 633 that form the infrared LED unit 63, based onan instruction received from the administrative controller 611. Thelight receiving controller 613 that functions as a light receivingsetting unit controls a light receiving operation of the infrared CMOS64 based on an instruction received from the administrative controller611. The image processor 614 that functions as an information acquiringunit and an information acquiring setting unit performs an imageprocessing for a received-light data inputted from the infrared CMOS 64,and then outputs the result to the communication unit 66, based on aninstruction received from the administrative controller 611.

FIG. 6B is a block diagram of a configuration of the image processor 614shown in FIG. 6A.

The image processor 614 which functions as an example of an analyzeraccording to the present exemplary embodiment includes a binaryprocessor 614 a, a dot detector 614 b and a code analyzer 614 c.

The binary processor 614 a outputs the received-light data inputted fromthe infrared CMOS 64 by binarizing each image element. The dot detector614 b detects dots from the binalized received-light data. The codeanalyzer 614 c analyzes the code pattern from an arrangement of thedetected dots, acquires information such as the identity information andthe location information from the analyzed code pattern, and outputs theacquired information to the communication unit 66. The informationoutputted from the code analyzer 614 c is temporarily stored in theinformation memory 65 as necessary.

As mentioned later, the various processings performed by the binaryprocessor 614 a, the dot detector 614 b and the code analyzer 614 c aredifferent depending on whether the digital pen 600 is set to the writingmode or the reference information acquiring mode. The processingsperformed by the binary processor 614 a, the dot detector 614 b and thecode analyzer 614 c change based on the instruction received from theadministrative controller 611. In the following description, a binaryprocessing performed by the binary processor 614 a, a dot detectionprocessing performed by the dot detector 614 b and a code analysisprocessing performed by the code analyzer 614 c are collectivelyreferred to as “a decoding processing.”

Here, the printed material 500 that is to be written or read by thedigital pen 600 is described with referring to an example. FIG. 7 showsa carte form of a carte sheet 510 as an example of the printed material500. In an image forming apparatus 400 shown in FIG. 1, by using thevisible toner, layout information such as ruled lines of the carte formis printed on the carte sheet 510. At the same time, in the imageforming apparatus 400, by using the invisible toner, a carte ID which isan example of the identity information to uniquely specify the sheet oneby one, and the code pattern image which indicates the locationinformation (coordinate information) on the carte sheet 510 are printedon the entire surface of the carte sheet 510.

As shown in FIG. 7, the carte form of the carte sheet 510 includes apatient basic information entry field 511 for filling in a patient'sname, the birth date, the patient's face photo, the previous disease,the allergy information and the like, and a handwriting informationentry field 512 corresponding to, for example, a carte form of a secondformat. In addition, the carte form includes an entry type selectionfield 513, a past history information reference field 514 and a systemlinking function field 515. On the carte form, a transparent image 516is additionally formed using the invisible toner.

As mentioned above, on the entire surface of the carte sheet 510, thecarte ID as an example of the identity information, and the locationinformation on the sheet are printed as a code pattern image. If ahandwriting input is performed on the carte sheet 510 using the digitalpen 600 that reads the code pattern image, the carte ID and the locationinformation are detected by the digital pen 600 at the same time. Withthe above operation, the digital pen 600 acquires information of thecarte sheet 510 currently used and of the location on which thehandwriting input is performed, as electronic information. Since atransparent image 516 is printed using the invisible toner, the printedcarte sheet 510 is visually confirmed to be a sheet on which the codepattern image including the identity information and the locationinformation with the invisible toner is printed by the difference ofbrightness between the transparent image 516 and the carte sheet 510.

For the medical examination of a patient, a doctor enters a medicalrecords into the handwriting information entry field 512 formed in thecarte form of the carte sheet 510 using the digital pen 600. At thistime, the digital pen 600 is set to the writing mode by an operation ofthe switch 68. The digital pen 600 reads the printed code pattern image,detects the carte ID and the moving trace of the digital pen 600 on thecarte sheet 510, and recognizes the carte and the content of thehandwriting input. Then, the handwriting result is displayed bysuperimposed on the electronic document that is a source of the cartesheet 510 on the terminal apparatus 700.

The contents that are filled in the handwriting information entry field512 of the carte sheet 510 includes, for example, contents associatedwith S, O, A and P shown in the entry type selection field 513 in FIG.7. For example, a patient's subjective information is entered byspecifying the subjective complaint (S: subjective). The doctor'smedical examination observation and inspection observation are enteredby specifying the objective finding (O: objective). The assessment, thediscrimination assessment, the medical treatment selection and thereason, and the evaluation of the medical treatment by the doctor areentered by specifying the assessment (A: assessment). The medicaltreatment plan and others are entered by specifying the plan (P: plan).

When a doctor needs to make reference to, for example, the past medicalhistory that is not described in the carte sheet 510 during a medicalexamination for a patient, the doctor makes a click on “□” column in thepast history information reference field 514 formed on the carte form ofthe carte sheet 510, that is, a specific area, using the digital pen600. At this time, the digital pen 600 is set to the referenceinformation acquiring mode by the operation of the switch 68. Thedigital pen 600 reads a code pattern image printed within “□” in thepast history information reference field 514, and recognizes the carteID and the location information of the digital pen 600 on the cartesheet 510. Thus, an electronic document corresponding to the carte IDand the location information is read out and displayed on the terminalapparatus 700.

When a doctor needs to make reference to the test status, the treatmentstatus, the prescription status and the reservation status of thepatient that are not described in the above carte sheet 510, the doctormakes a click on the corresponding “□” column of the system linkingfunction field 515 formed on the carte form of the carte sheet 510, thatis, a specific area, using the digital pen 600. Then, the carte ID andthe location information are acquired from the read code pattern image,and an electronic document corresponding thereto is displayed on theterminal apparatus 700.

Next, an operation setting of the digital pen 600 is described below.The operation setting in the writing mode of the digital pen 600according to the present exemplary embodiment is set differently fromthat in the reference information acquiring mode.

FIG. 8A is a flowchart showing the flow of the operation setting of thedigital pen 600 in the writing mode.

If setting to the writing mode is received via the switch 68, theadministrative controller 611 outputs a control signal to the lightemitting controller 612, the light receiving controller 613 and theimage processor 614. Following the above, the light emitting controller612 sets an emitting condition, that is, a light emitting condition, ofthe infrared LED unit 63 to a first light emitting condition (step 101),the light receiving controller 613 sets the light receiving condition ofthe infrared CMOS 64 to a first light receiving condition (step 102),and the image processor 614 sets the image processing conditions of thebinary processor 614 a, the dot detector 614 b and the code analyzer 614c to first image processing conditions (step 103).

On the other hand, FIG. 8B is a flowchart showing the flow of theoperation setting of the digital pen 600 in the reference informationacquiring mode.

If setting to the reference information acquiring mode is received viathe switch 68, the administrative controller 611 outputs a controlsignal to the light emitting controller 612, the light receivingcontroller 613 and the image processor 614. Following the above, thelight emitting controller 612 sets an emitting condition, that is, thelight emitting condition, of the infrared LED unit 63 to a second lightemitting condition (step 201), the light receiving controller 613 sets alight receiving condition of the infrared CMOS 64 to a second lightreceiving condition (step 202), and the image processor 614 sets imageprocessing conditions of the binary processor 614 a, the dot detector614 b, and the code analyzer 614 c to second image processing conditions(step 203).

Here, FIG. 9A shows an example of the first light emitting condition andthe second light emitting condition which are set in the infrared LEDunit 63.

In the first light emitting condition, among the three infrared LEDs,only the first infrared LED 631, that is, only one LED, is subject toemit the light. Thus, the printed material 500 has an infrared lightemission range of, for example, approximately 5 mm by 5 mm. In the firstlight emitting condition, the drive frequency of the first infrared LED631 that is to emit the light is set to 60 Hz, the drive pulse width isset to 1 ms or less and the drive current is set in a range from 50 to100 mA.

On the other hand, in the second light emitting condition, the threeinfrared LEDs, that is, all of the first infrared LED 631, the secondinfrared LED 632 and the third infrared LED 633, are to emit the light.Thus, the infrared light emission range of the printed material 500 is,for example, approximately a range of 10 mm by 10 mm, which is widerthan that in the first light emitting condition. In the second lightemitting condition, the drive frequency of the first infrared LED 631,the second infrared LED 632 and the third infrared LED 633 that are toemit the light is set to 10 Hz, the drive pulse width is set to 50 ms ormore, and the drive current is set to a value higher than 100 mA.

FIG. 9B shows an example of the first light receiving condition and thesecond light receiving condition which are set to the infrared CMOS 64.

In the first light receiving condition, the read range of the printedmaterial 500 with the infrared CMOS chip 641 is set to a range of 5 mmby 5 mm, that is, the range of the first light receiving area 644 shownin FIG. 5, and the acquired line is set to a half number of lines thatis every other lines in all lines. In the first light receivingcondition, the drive frequency of the infrared CMOS chip 641 that is toreceive the light is set to 60 Hz.

On the other hand, in the second light receiving condition, the readrange of the printed material 500 with the infrared CMOS chip 641 is setto a range of 10 mm by 10 mm, that is, the range of the second lightreceiving area 645 shown in FIG. 5, and acquired lines are set to alllines. In the second light receiving condition, the drive frequency ofthe infrared CMOS chip 641 that is to receive the light is set to 10 Hz.

Further, FIG. 9C shows an example of the first image processingcondition and the second image processing condition which are set to theimage processor 614.

In the first image processing condition, the binary processor 614 aperforms a processing using a one-dimensional filter. In the first imageprocessing condition, the dot detector 614 b performs a processing foreach line, that is, a one-dimensional dot detection processing. Further,the code analyzer 614 c performs the code analysis processing only oncefor the detected dot.

On the other hand, in the second image processing condition, the binaryprocessor 614 a performs a processing using a two-dimensional filter. Inthe second image processing condition, the dot detector 614 b performs aprocessing for each area including plural lines, that is, atwo-dimensional dot detection processing. The code analyzer 614 cperforms the code analysis processing plural times for the detecteddots.

In the writing mode, the drive frequency of the infrared LED unit 63 andthe infrared CMOS 64 is set to 60 Hz, resulting in 60 infrared imagesacquired per second. Each of the acquired infrared images corresponds toa size of 5 mm by 5 mm on the carte sheet 510, and the resolution is setto 300 dpi.

On the other hand, in the reference information acquiring mode, thedrive frequency of the infrared LED unit 63 and the infrared CMOS 64 isset to 10 Hz, resulting in 10 infrared images acquired per second. Eachof the acquired infrared images corresponds to a size of 10 mm by 10 mmon the carte sheet 510, and the resolution at the time is set to 600dpi.

In other words, according to the present exemplary embodiment, thenumber of the infrared images acquired per unit time in the writingmode, that is, the number of the acquired images, is larger than thenumber of the acquired images per unit time in the reference informationacquiring mode.

In the writing mode, a writing operation is continuously performed onthe same carte sheet 510. The infrared image data acquired by thewriting operation is configured by one or plural strokes, each of whichis formed by plural consecutive images. In one stroke, the tip of thedigital pen 600 never moves to another carte sheet 510 or a distantlocation. Thus, even when the decode ratio per one infrared image(acquiring precision of the carte ID and the location information) islower to some extent, there may be no problems as long as the carte IDand the location information are comprehensively acquired from theplural infrared images included in one stroke. For example, in casewhere a stroke is configured by ten infrared images, if each infraredimage has an error recognition ratio of 10%, the total value becomes10⁻¹⁰%, which causes no problems practically. For example, even if astroke includes a few or less infrared images in such a case where apoint appearing in characters like “i” and “j” is entered, strokes thatis consecutively performed in a short time may have a higher possibilitythat the strokes are performed in the same document and the latterstroke is located near the former stroke, as the time interval becomesnarrower. Thus, taking all into consideration comprehensively, even ifthe error recognition ratio of one infrared image takes a higher valueto some degree, this causes no problems practically. In the writingmode, the content written by the digital pen 600 remains on the cartesheet 510. Thus, there is no necessity to send immediately the writteninformation to the terminal apparatus 700 for display but the writteninformation may be sent to the terminal apparatus 700 after one strokeor a series of writing operation is completed and comprehensive judgmenton the carte ID and the location information are made in the imageprocessor 614. Then, in the writing mode, as 60 infrared images areacquired in a second, the data amount per unit time tends to increasewhile a shorter decoding speed per one infrared image is furtherrequired.

On the other hand, in the reference information acquiring mode, forexample, by making one click on a specific area such as “□” column onthe past history information reference field 514, it is required tosecurely refer to a link destination such as an electronic document.Unlike in the writing mode, the tip location of the digital pen 600hardly changes within one stroke. Thus, in the reference informationacquiring mode, the number of the infrared images used for the decodemay be less than that in the writing mode, but it is required todecrease the error recognition ratio per an infrared image lower thanthat in the writing mode.

For this purpose, in the present exemplary embodiment, depending on afunction required in the writing mode and in the reference informationacquiring mode, levels of the light emission control, the lightreceiving control and the image processing are to be changed.

For example, in the writing mode, the number of the acquired infraredimages per unit time is made larger than that in the referenceinformation acquiring mode while the read area is made smaller than thatin the reference information acquiring mode and the read resolution isalso made lower than that in the reference information acquiring mode,so that the data amount per one infrared image is made smaller than thatin the reference information acquiring mode. In other words, the readprecision of the infrared image in the writing mode is lower than thatin the reference information acquiring mode. Additionally, in thewriting mode, the quantity of the infrared light emitted from theinfrared LED unit 63 is made smaller than that in the referenceinformation acquiring mode to save the power consumption. Further, inthe writing mode, light emitting duration of the infrared light emittedfrom the infrared LED unit 63 at one time is made shorter than that inthe reference information acquiring mode, to reduce a blur of theacquired infrared image. Moreover, in the writing mode, the content ofthe image processing in the image processor 614, that is, the acquiringprecisions of the carte ID and the location information, is made lowerthan that in the reference information acquiring mode, so that theprocessing time taken per one infrared image is made shorter than thatin the reference information acquiring mode.

On the other hand, in the reference information acquiring mode, thenumber of the acquired infrared images per unit time is made smallerthan that in the writing mode while the read area is made larger thanthat in the writing mode and the read resolution is also made higherthan that in the writing mode so that the data amount per one infraredimage is made larger than that in the writing mode. In other words, theread precision of the infrared image in the reference informationacquiring mode is made higher than that in the writing mode.Additionally, in the reference information acquiring mode, the quantityof the infrared light emitted from the infrared LED unit 63 is madelarger than that in the writing mode, and infrared image with highercontrast than that in the writing mode is acquired. In addition, in thereference information acquiring mode, light emitting duration of theinfrared light emitted from infrared LED unit 63 at one time is madelonger than that in the writing mode so that the precision of acquiredinfrared image is increased. Moreover, the content of the imageprocessing in the image processor 614, that is, the acquiring precisionof the carte ID and the location information, is made higher than thatin the writing mode, so that the carte ID and the location informationare precisely acquired from a few infrared images.

According to the present exemplary embodiment, both in the writing modeand in the reference information acquiring mode, the decoding processingis performed in the digital pen 600. However, it is not limited to thiscase. For example, in the reference information acquiring mode, theinfrared image data acquired by the digital pen 600 is directly sent tothe terminal apparatus 700, and then the terminal apparatus 700 mayperform the decoding processing. In the writing mode, the number of theinfrared images acquired per unit time is more than that in thereference information acquiring mode, thus the decoding processingbecomes more efficient if performed in the digital pen 600. However, inthe writing mode, all the decoding processing may not be necessarilyperformed in the digital pen 600, and, for example, the transmission maybe performed after performing only the binary processing or afterperforming the binary processing and the dot detection processing.

In the present exemplary embodiment, both the read range and the readresolution of the infrared images are changed in the writing mode and inthe reference information acquiring mode. However, instead of that, anyone of them may be changed. Further, in the present exemplaryembodiment, both the number of the infrared LEDs that emit the infraredlight and the drive current supplied to the infrared LED are changed inthe writing mode and the reference information acquiring mode. However,instead of that, any one of them may be changed.

The foregoing description of the exemplary embodiments of the presentinvention has been provided for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in the art. Thepresent exemplary embodiments were chosen and described in order to bestexplain the principles of the invention and its practical applications,thereby enabling others skilled in the art to understand the inventionfor various embodiments and with the various modifications as are suitedto the particular use contemplated. It is intended that the scope of theinvention be defined by the following claims and their equivalents.

1. An electronic writing instrument comprising: a writing unit thatwrites down on a medium where a code indicating identity information andlocation information of the medium is formed; an emitting unit thatemits light to the medium; a photoelectric conversion unit that includesa photoelectric conversion element receiving a reflected light from themedium by the light emitted by the emitting unit and outputting anelectronic signal after converting the reflected light by photoelectricconversion; a receiving unit that receives a user operation; and acondition changing unit that changes, in response to the receiving unitreceiving the user operation, at least one of: an emitting condition ofthe emitting unit from a first emitting condition in which light isemitted to the medium to a second emitting condition in which light isemitted to the medium; and an output condition of the photoelectricconversion unit when receiving the reflected light from the medium. 2.The electronic writing instrument according to claim 1, wherein thecondition changing unit changes, as the emitting condition, at least anyone of the number of the emission per unit time, quantity of the emittedlight per unit time and an emission range to the medium by the emittingunit.
 3. The electronic writing instrument according to claim 1, whereinthe condition changing unit changes, as the output condition, at leastanyone of the number of the photoelectric conversion elements thatperforms outputs after the photoelectric conversion and the number ofthe outputs per unit time of the photoelectric conversion unit.
 4. Theelectronic writing instrument according to claim 1, further comprising:an acquiring unit that acquires a code image formed on the medium,wherein the acquiring unit, according to the operation received by thereceiving unit, switches between a first acquiring mode and a secondacquiring mode, the first acquiring mode acquiring the predeterminednumber of code images per unit time with a predetermined image size, thesecond acquiring mode acquiring the number of code images per unit timesmaller than the number of the code images per unit time in the firstacquiring mode, with an image size per acquired code image larger thanthe image size per acquired code image in the first acquiring mode. 5.The electronic writing instrument according to claim 1, furthercomprising: an acquiring unit that acquires a code image formed on themedium; and an information acquiring unit that decodes the code imageacquired by the acquiring unit, and acquires the identity informationand the location information, wherein the condition changing unitchanges an information acquiring condition of the information acquiringunit.
 6. The electronic writing instrument according to claim 1, whereinthe condition changing unit changes the at least one of the emittingcondition and the output condition to thereby change from a writing modeto a reference information acquiring mode, wherein the receiving unitthat has a physical switch for changing the at least one of the emittingcondition and the output condition to thereby change from the writingmode to the reference information acquiring mode.